Diff
Modified: trunk/Source/WebCore/ChangeLog (162701 => 162702)
--- trunk/Source/WebCore/ChangeLog 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/ChangeLog 2014-01-24 17:14:22 UTC (rev 162702)
@@ -1,3 +1,69 @@
+2014-01-21 David Hyatt <hy...@apple.com>
+
+ [New Multicolumn] Table cells and list items need to work as multicolumn blocks.
+ https://bugs.webkit.org/show_bug.cgi?id=127365
+
+ This patch is a first step towards eliminating RenderMultiColumnBlock and moving
+ all its functionality into RenderBlockFlow. Doing so will allow table cells, list
+ items and the RenderView to use the new multi-column layout.
+
+ Reviewed by Simon Fraser.
+
+ * rendering/RenderBlockFlow.cpp:
+ (WebCore::RenderBlockFlow::setMultiColumnFlowThread):
+ * rendering/RenderBlockFlow.h:
+ (WebCore::RenderBlockFlow::RenderBlockFlowRareData::RenderBlockFlowRareData):
+ (WebCore::RenderBlockFlow::multiColumnFlowThread):
+ Add the flow thread pointer to the multi-column flow thread to RenderBlockFlow's
+ rare data. This lets us use only one pointer in the rare data to point to an object
+ that can hold all of the rest of the multi-column info.
+
+ * rendering/RenderMultiColumnBlock.cpp:
+ (WebCore::RenderMultiColumnBlock::RenderMultiColumnBlock):
+ Move the construction of the flow thread to the constructor. This ensures we
+ never have a null flow thread and lets us avoid having to null check it for
+ empty multi-column blocks.
+
+ (WebCore::RenderMultiColumnBlock::columnHeightAvailable):
+ (WebCore::RenderMultiColumnBlock::columnWidth):
+ (WebCore::RenderMultiColumnBlock::columnCount):
+ (WebCore::RenderMultiColumnBlock::updateLogicalWidthAndColumnWidth):
+ The above functions now call through to the multi-column flow thread for results.
+
+ (WebCore::RenderMultiColumnBlock::checkForPaginationLogicalHeightChange):
+ Set the column height available on the flow thread.
+
+ (WebCore::RenderMultiColumnBlock::relayoutForPagination):
+ The balancing pass and guard is in the multi-column flow thread now.
+
+ (WebCore::RenderMultiColumnBlock::addChild):
+ Don't have to create the flow thread here any longer, since we do it up front
+ in the constructor of RenderMultiColumnBlock.
+
+ (WebCore::RenderMultiColumnBlock::layoutSpecialExcludedChild):
+ Don't need the null check of the flow thread any more.
+
+ * rendering/RenderMultiColumnBlock.h:
+ Change the inlined functions to not be inlined, since they need to call
+ RenderMultiColumnFlowThread functions now.
+
+ * rendering/RenderMultiColumnFlowThread.cpp:
+ (WebCore::RenderMultiColumnFlowThread::RenderMultiColumnFlowThread):
+ Init the new member variables we moved here from RenderMultiColumnBlock.
+
+ (WebCore::RenderMultiColumnFlowThread::computeColumnCountAndWidth):
+ Moved from RenderMultiColumnBlock.
+
+ * rendering/RenderMultiColumnFlowThread.h:
+ Add public getters/setters to the member variables so that RenderMultiColumnBlock can
+ still see them. Move the member variables here from RenderMultiColumnBlock.
+
+ * rendering/RenderMultiColumnSet.cpp:
+ (WebCore::RenderMultiColumnSet::calculateBalancedHeight):
+ (WebCore::RenderMultiColumnSet::prepareForLayout):
+ (WebCore::RenderMultiColumnSet::columnCount):
+ Call through to the flow thread instead.
+
2014-01-24 Zan Dobersek <zdober...@igalia.com>
Unreviewed GTK build fix after r162663.
Modified: trunk/Source/WebCore/rendering/RenderBlockFlow.cpp (162701 => 162702)
--- trunk/Source/WebCore/rendering/RenderBlockFlow.cpp 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/rendering/RenderBlockFlow.cpp 2014-01-24 17:14:22 UTC (rev 162702)
@@ -2890,6 +2890,12 @@
rareData.m_renderNamedFlowFragment = flowFragment;
}
+void RenderBlockFlow::setMultiColumnFlowThread(RenderMultiColumnFlowThread* flowThread)
+{
+ RenderBlockFlowRareData& rareData = ensureRareBlockFlowData();
+ rareData.m_multiColumnFlowThread = flowThread;
+}
+
static bool shouldCheckLines(const RenderBlockFlow& blockFlow)
{
return !blockFlow.isFloatingOrOutOfFlowPositioned() && !blockFlow.isRunIn() && blockFlow.style().height().isAuto();
Modified: trunk/Source/WebCore/rendering/RenderBlockFlow.h (162701 => 162702)
--- trunk/Source/WebCore/rendering/RenderBlockFlow.h 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/rendering/RenderBlockFlow.h 2014-01-24 17:14:22 UTC (rev 162702)
@@ -35,6 +35,7 @@
class LineBreaker;
class LineInfo;
class LineWidth;
+class RenderMultiColumnFlowThread;
class RenderNamedFlowFragment;
class RenderRubyRun;
@@ -117,6 +118,7 @@
: m_margins(positiveMarginBeforeDefault(block), negativeMarginBeforeDefault(block), positiveMarginAfterDefault(block), negativeMarginAfterDefault(block))
, m_lineBreakToAvoidWidow(-1)
, m_renderNamedFlowFragment(nullptr)
+ , m_multiColumnFlowThread(nullptr)
, m_discardMarginBefore(false)
, m_discardMarginAfter(false)
, m_didBreakAtLineToAvoidWidow(false)
@@ -149,6 +151,8 @@
std::unique_ptr<RootInlineBox> m_lineGridBox;
RenderNamedFlowFragment* m_renderNamedFlowFragment;
+ RenderMultiColumnFlowThread* m_multiColumnFlowThread;
+
bool m_discardMarginBefore : 1;
bool m_discardMarginAfter : 1;
bool m_didBreakAtLineToAvoidWidow : 1;
@@ -270,6 +274,9 @@
RenderNamedFlowFragment* renderNamedFlowFragment() const { return hasRareBlockFlowData() ? rareBlockFlowData()->m_renderNamedFlowFragment : nullptr; }
void setRenderNamedFlowFragment(RenderNamedFlowFragment*);
+ RenderMultiColumnFlowThread* multiColumnFlowThread() const { return hasRareBlockFlowData() ? rareBlockFlowData()->m_multiColumnFlowThread : nullptr; }
+ void setMultiColumnFlowThread(RenderMultiColumnFlowThread*);
+
bool containsFloats() const override { return m_floatingObjects && !m_floatingObjects->set().isEmpty(); }
bool containsFloat(RenderBox&) const;
Modified: trunk/Source/WebCore/rendering/RenderMultiColumnBlock.cpp (162701 => 162702)
--- trunk/Source/WebCore/rendering/RenderMultiColumnBlock.cpp 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/rendering/RenderMultiColumnBlock.cpp 2014-01-24 17:14:22 UTC (rev 162702)
@@ -33,56 +33,47 @@
namespace WebCore {
-RenderMultiColumnBlock::RenderMultiColumnBlock(Element& element, PassRef<RenderStyle> style)
- : RenderBlockFlow(element, std::move(style))
- , m_flowThread(0)
- , m_columnCount(1)
- , m_columnWidth(0)
- , m_columnHeightAvailable(0)
- , m_inBalancingPass(false)
- , m_needsRebalancing(false)
+RenderMultiColumnBlock::RenderMultiColumnBlock(Element& element, PassRef<RenderStyle> stylePtr)
+ : RenderBlockFlow(element, std::move(stylePtr))
{
+ setChildrenInline(false);
+ RenderMultiColumnFlowThread* flowThread = new RenderMultiColumnFlowThread(document(), RenderStyle::createAnonymousStyleWithDisplay(&style(), BLOCK));
+ flowThread->initializeStyle();
+ RenderBlockFlow::addChild(flowThread);
+ setMultiColumnFlowThread(flowThread);
}
-void RenderMultiColumnBlock::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
+bool RenderMultiColumnBlock::requiresBalancing() const
{
- RenderBlockFlow::styleDidChange(diff, oldStyle);
- for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox())
- child->setStyle(RenderStyle::createAnonymousStyleWithDisplay(&style(), BLOCK));
+ return multiColumnFlowThread()->requiresBalancing();
}
-void RenderMultiColumnBlock::computeColumnCountAndWidth()
+LayoutUnit RenderMultiColumnBlock::columnHeightAvailable() const
{
- // Calculate our column width and column count.
- // FIXME: Can overflow on fast/block/float/float-not-removed-from-next-sibling4.html, see https://bugs.webkit.org/show_bug.cgi?id=68744
- m_columnCount = 1;
- m_columnWidth = contentLogicalWidth();
-
- ASSERT(!style().hasAutoColumnCount() || !style().hasAutoColumnWidth());
+ return multiColumnFlowThread()->columnHeightAvailable();
+}
- LayoutUnit availWidth = m_columnWidth;
- LayoutUnit colGap = columnGap();
- LayoutUnit colWidth = std::max<LayoutUnit>(1, LayoutUnit(style().columnWidth()));
- int colCount = std::max<int>(1, style().columnCount());
+LayoutUnit RenderMultiColumnBlock::columnWidth() const
+{
+ return multiColumnFlowThread()->columnWidth();
+}
- if (style().hasAutoColumnWidth() && !style().hasAutoColumnCount()) {
- m_columnCount = colCount;
- m_columnWidth = std::max<LayoutUnit>(0, (availWidth - ((m_columnCount - 1) * colGap)) / m_columnCount);
- } else if (!style().hasAutoColumnWidth() && style().hasAutoColumnCount()) {
- m_columnCount = std::max<LayoutUnit>(1, (availWidth + colGap) / (colWidth + colGap));
- m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap;
- } else {
- m_columnCount = std::max<LayoutUnit>(std::min<LayoutUnit>(colCount, (availWidth + colGap) / (colWidth + colGap)), 1);
- m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap;
- }
+unsigned RenderMultiColumnBlock::columnCount() const
+{
+ return multiColumnFlowThread()->columnCount();
}
+
+void RenderMultiColumnBlock::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
+{
+ RenderBlockFlow::styleDidChange(diff, oldStyle);
+ for (RenderBox* child = firstChildBox(); child; child = child->nextSiblingBox())
+ child->setStyle(RenderStyle::createAnonymousStyleWithDisplay(&style(), BLOCK));
+}
bool RenderMultiColumnBlock::updateLogicalWidthAndColumnWidth()
{
bool relayoutChildren = RenderBlockFlow::updateLogicalWidthAndColumnWidth();
- LayoutUnit oldColumnWidth = m_columnWidth;
- computeColumnCountAndWidth();
- if (m_columnWidth != oldColumnWidth)
+ if (multiColumnFlowThread()->computeColumnCountAndWidth())
relayoutChildren = true;
return relayoutChildren;
}
@@ -91,16 +82,17 @@
{
// We don't actually update any of the variables. We just subclassed to adjust our column height.
updateLogicalHeight();
- m_columnHeightAvailable = std::max<LayoutUnit>(contentLogicalHeight(), 0);
+ multiColumnFlowThread()->setColumnHeightAvailable(std::max<LayoutUnit>(contentLogicalHeight(), 0));
setLogicalHeight(0);
}
bool RenderMultiColumnBlock::relayoutForPagination(bool, LayoutUnit, LayoutStateMaintainer& statePusher)
{
- if (m_inBalancingPass || !m_needsRebalancing)
+ if (!multiColumnFlowThread()->shouldRelayoutForPagination())
return false;
- m_needsRebalancing = false;
- m_inBalancingPass = true; // Prevent re-entering this method (and recursion into layout).
+
+ multiColumnFlowThread()->setNeedsRebalancing(false);
+ multiColumnFlowThread()->setInBalancingPass(true); // Prevent re-entering this method (and recursion into layout).
bool needsRelayout;
bool neededRelayout = false;
@@ -113,7 +105,7 @@
// columns, unless we have a bug.
needsRelayout = false;
for (RenderBox* childBox = firstChildBox(); childBox; childBox = childBox->nextSiblingBox())
- if (childBox != m_flowThread && childBox->isRenderMultiColumnSet()) {
+ if (childBox != multiColumnFlowThread() && childBox->isRenderMultiColumnSet()) {
RenderMultiColumnSet* multicolSet = toRenderMultiColumnSet(childBox);
if (multicolSet->recalculateBalancedHeight(firstPass)) {
multicolSet->setChildNeedsLayout(MarkOnlyThis);
@@ -124,7 +116,7 @@
if (needsRelayout) {
// Layout again. Column balancing resulted in a new height.
neededRelayout = true;
- m_flowThread->setChildNeedsLayout(MarkOnlyThis);
+ multiColumnFlowThread()->setChildNeedsLayout(MarkOnlyThis);
setChildNeedsLayout(MarkOnlyThis);
if (firstPass)
statePusher.pop();
@@ -132,47 +124,41 @@
}
firstPass = false;
} while (needsRelayout);
- m_inBalancingPass = false;
+
+ multiColumnFlowThread()->setInBalancingPass(false);
+
return neededRelayout;
}
void RenderMultiColumnBlock::addChild(RenderObject* newChild, RenderObject* beforeChild)
{
- if (!m_flowThread) {
- m_flowThread = new RenderMultiColumnFlowThread(document(), RenderStyle::createAnonymousStyleWithDisplay(&style(), BLOCK));
- m_flowThread->initializeStyle();
- RenderBlockFlow::addChild(m_flowThread);
- }
- m_flowThread->addChild(newChild, beforeChild);
+ multiColumnFlowThread()->addChild(newChild, beforeChild);
}
RenderObject* RenderMultiColumnBlock::layoutSpecialExcludedChild(bool relayoutChildren)
{
- if (!m_flowThread)
- return 0;
-
// Update the dimensions of our regions before we lay out the flow thread.
// FIXME: Eventually this is going to get way more complicated, and we will be destroying regions
// instead of trying to keep them around.
bool shouldInvalidateRegions = false;
for (RenderBox* childBox = firstChildBox(); childBox; childBox = childBox->nextSiblingBox()) {
- if (childBox == m_flowThread)
+ if (childBox == multiColumnFlowThread())
continue;
if (relayoutChildren || childBox->needsLayout()) {
- if (!m_inBalancingPass && childBox->isRenderMultiColumnSet())
+ if (!multiColumnFlowThread()->inBalancingPass() && childBox->isRenderMultiColumnSet())
toRenderMultiColumnSet(childBox)->prepareForLayout();
shouldInvalidateRegions = true;
}
}
if (shouldInvalidateRegions)
- m_flowThread->invalidateRegions();
+ multiColumnFlowThread()->invalidateRegions();
if (relayoutChildren)
- m_flowThread->setChildNeedsLayout(MarkOnlyThis);
+ multiColumnFlowThread()->setChildNeedsLayout(MarkOnlyThis);
- if (requiresBalancing()) {
+ if (multiColumnFlowThread()->requiresBalancing()) {
// At the end of multicol layout, relayoutForPagination() is called unconditionally, but if
// no children are to be laid out (e.g. fixed width with layout already being up-to-date),
// we want to prevent it from doing any work, so that the column balancing machinery doesn't
@@ -181,14 +167,14 @@
// are actually required to guarantee this. The calculation of implicit breaks needs to be
// preceded by a proper layout pass, since it's layout that sets up content runs, and the
// runs get deleted right after every pass.
- m_needsRebalancing = shouldInvalidateRegions || m_flowThread->needsLayout();
+ multiColumnFlowThread()->setNeedsRebalancing(shouldInvalidateRegions || multiColumnFlowThread()->needsLayout());
}
- setLogicalTopForChild(*m_flowThread, borderAndPaddingBefore());
- m_flowThread->layoutIfNeeded();
- determineLogicalLeftPositionForChild(*m_flowThread);
+ setLogicalTopForChild(*multiColumnFlowThread(), borderAndPaddingBefore());
+ multiColumnFlowThread()->layoutIfNeeded();
+ determineLogicalLeftPositionForChild(*multiColumnFlowThread());
- return m_flowThread;
+ return multiColumnFlowThread();
}
const char* RenderMultiColumnBlock::renderName() const
Modified: trunk/Source/WebCore/rendering/RenderMultiColumnBlock.h (162701 => 162702)
--- trunk/Source/WebCore/rendering/RenderMultiColumnBlock.h 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/rendering/RenderMultiColumnBlock.h 2014-01-24 17:14:22 UTC (rev 162702)
@@ -38,15 +38,13 @@
RenderMultiColumnBlock(Element&, PassRef<RenderStyle>);
Element& element() const { return toElement(nodeForNonAnonymous()); }
- LayoutUnit columnHeightAvailable() const { return m_columnHeightAvailable; }
+ LayoutUnit columnHeightAvailable() const;
- LayoutUnit columnWidth() const { return m_columnWidth; }
- unsigned columnCount() const { return m_columnCount; }
+ LayoutUnit columnWidth() const;
+ unsigned columnCount() const;
- RenderMultiColumnFlowThread* flowThread() const { return m_flowThread; }
-
- bool requiresBalancing() const { return !m_columnHeightAvailable || style().columnFill() == ColumnFillBalance; }
-
+ bool requiresBalancing() const;
+
private:
virtual bool isRenderMultiColumnBlock() const { return true; }
virtual const char* renderName() const;
@@ -64,14 +62,6 @@
void computeColumnCountAndWidth();
void ensureColumnSets();
-
- RenderMultiColumnFlowThread* m_flowThread;
- unsigned m_columnCount; // The default column count/width that are based off our containing block width. These values represent only the default,
- LayoutUnit m_columnWidth; // since a multi-column block that is split across variable width pages or regions will have different column counts and widths in each.
- // These values will be cached (eventually) for multi-column blocks.
- LayoutUnit m_columnHeightAvailable; // Total height available to columns, or 0 if auto.
- bool m_inBalancingPass; // Set when relayouting for column balancing.
- bool m_needsRebalancing;
};
RENDER_OBJECT_TYPE_CASTS(RenderMultiColumnBlock, isRenderMultiColumnBlock())
Modified: trunk/Source/WebCore/rendering/RenderMultiColumnFlowThread.cpp (162701 => 162702)
--- trunk/Source/WebCore/rendering/RenderMultiColumnFlowThread.cpp 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/rendering/RenderMultiColumnFlowThread.cpp 2014-01-24 17:14:22 UTC (rev 162702)
@@ -33,6 +33,11 @@
RenderMultiColumnFlowThread::RenderMultiColumnFlowThread(Document& document, PassRef<RenderStyle> style)
: RenderFlowThread(document, std::move(style))
+ , m_columnCount(1)
+ , m_columnWidth(0)
+ , m_columnHeightAvailable(0)
+ , m_inBalancingPass(false)
+ , m_needsRebalancing(false)
{
setFlowThreadState(InsideInFlowThread);
}
@@ -59,6 +64,40 @@
return parentBlock->columnWidth();
}
+bool RenderMultiColumnFlowThread::computeColumnCountAndWidth()
+{
+ RenderBlock* columnBlock = toRenderBlock(parent());
+
+ LayoutUnit oldColumnWidth = m_columnWidth;
+
+ // Calculate our column width and column count.
+ // FIXME: Can overflow on fast/block/float/float-not-removed-from-next-sibling4.html, see https://bugs.webkit.org/show_bug.cgi?id=68744
+ m_columnCount = 1;
+ m_columnWidth = columnBlock->contentLogicalWidth();
+
+ const RenderStyle& columnStyle = columnBlock->style();
+
+ ASSERT(!columnStyle.hasAutoColumnCount() || !columnStyle.hasAutoColumnWidth());
+
+ LayoutUnit availWidth = m_columnWidth;
+ LayoutUnit colGap = columnBlock->columnGap();
+ LayoutUnit colWidth = std::max<LayoutUnit>(1, LayoutUnit(columnStyle.columnWidth()));
+ int colCount = std::max<int>(1, columnStyle.columnCount());
+
+ if (columnStyle.hasAutoColumnWidth() && !columnStyle.hasAutoColumnCount()) {
+ m_columnCount = colCount;
+ m_columnWidth = std::max<LayoutUnit>(0, (availWidth - ((m_columnCount - 1) * colGap)) / m_columnCount);
+ } else if (!columnStyle.hasAutoColumnWidth() && columnStyle.hasAutoColumnCount()) {
+ m_columnCount = std::max<LayoutUnit>(1, (availWidth + colGap) / (colWidth + colGap));
+ m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap;
+ } else {
+ m_columnCount = std::max<LayoutUnit>(std::min<LayoutUnit>(colCount, (availWidth + colGap) / (colWidth + colGap)), 1);
+ m_columnWidth = ((availWidth + colGap) / m_columnCount) - colGap;
+ }
+
+ return m_columnWidth != oldColumnWidth;
+}
+
void RenderMultiColumnFlowThread::autoGenerateRegionsToBlockOffset(LayoutUnit /*offset*/)
{
// This function ensures we have the correct column set information at all times.
Modified: trunk/Source/WebCore/rendering/RenderMultiColumnFlowThread.h (162701 => 162702)
--- trunk/Source/WebCore/rendering/RenderMultiColumnFlowThread.h 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/rendering/RenderMultiColumnFlowThread.h 2014-01-24 17:14:22 UTC (rev 162702)
@@ -36,6 +36,21 @@
RenderMultiColumnFlowThread(Document&, PassRef<RenderStyle>);
~RenderMultiColumnFlowThread();
+ unsigned columnCount() const { return m_columnCount; }
+ LayoutUnit columnWidth() const { return m_columnWidth; }
+ LayoutUnit columnHeightAvailable() const { return m_columnHeightAvailable; }
+ void setColumnHeightAvailable(LayoutUnit available) { m_columnHeightAvailable = available; }
+ bool inBalancingPass() const { return m_inBalancingPass; }
+ void setInBalancingPass(bool balancing) { m_inBalancingPass = balancing; }
+ bool needsRebalancing() const { return m_needsRebalancing; }
+ void setNeedsRebalancing(bool balancing) { m_needsRebalancing = balancing; }
+
+ bool computeColumnCountAndWidth();
+
+ bool shouldRelayoutForPagination() const { return !m_inBalancingPass && m_needsRebalancing; }
+
+ bool requiresBalancing() const { return !columnHeightAvailable() || parent()->style().columnFill() == ColumnFillBalance; }
+
private:
virtual const char* renderName() const override;
virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const override;
@@ -44,6 +59,14 @@
virtual void setPageBreak(const RenderBlock*, LayoutUnit offset, LayoutUnit spaceShortage) override;
virtual void updateMinimumPageHeight(const RenderBlock*, LayoutUnit offset, LayoutUnit minHeight) override;
virtual bool addForcedRegionBreak(const RenderBlock*, LayoutUnit, RenderBox* breakChild, bool isBefore, LayoutUnit* offsetBreakAdjustment = 0) override;
+
+private:
+ unsigned m_columnCount; // The default column count/width that are based off our containing block width. These values represent only the default,
+ LayoutUnit m_columnWidth; // A multi-column block that is split across variable width pages or regions will have different column counts and widths in each.
+ // These values will be cached (eventually) for multi-column blocks.
+ LayoutUnit m_columnHeightAvailable; // Total height available to columns, or 0 if auto.
+ bool m_inBalancingPass; // Guard to avoid re-entering column balancing.
+ bool m_needsRebalancing;
};
} // namespace WebCore
Modified: trunk/Source/WebCore/rendering/RenderMultiColumnSet.cpp (162701 => 162702)
--- trunk/Source/WebCore/rendering/RenderMultiColumnSet.cpp 2014-01-24 16:34:24 UTC (rev 162701)
+++ trunk/Source/WebCore/rendering/RenderMultiColumnSet.cpp 2014-01-24 17:14:22 UTC (rev 162702)
@@ -232,7 +232,7 @@
// Set box width.
updateLogicalWidth();
- if (multicolBlock->requiresBalancing()) {
+ if (multicolBlock->multiColumnFlowThread()->requiresBalancing()) {
// Set maximum column height. We will not stretch beyond this.
m_maxColumnHeight = RenderFlowThread::maxLogicalHeight();
if (!multicolStyle.logicalHeight().isAuto()) {
@@ -281,6 +281,9 @@
// Our portion rect determines our column count. We have as many columns as needed to fit all the content.
LayoutUnit logicalHeightInColumns = flowThread()->isHorizontalWritingMode() ? flowThreadPortionRect().height() : flowThreadPortionRect().width();
+ if (!logicalHeightInColumns)
+ return 1;
+
unsigned count = ceil(static_cast<float>(logicalHeightInColumns) / computedColumnHeight());
ASSERT(count >= 1);
return count;
